2-piperazin-1-ylethanol

Bioaccumulation: aquatic / sediment

Description of key information

Significant accumulation in organisms is not to be expected.

Additional information

QSAR-disclaimer:

In Article 13 of Regulation (EC) No 1907/2006, it is laid down that information on intrinsic properties of substances may be generated by means other than tests, provided that the conditions set out in Annex XI (of the same Regulation) are met. Furthermore according to Article 25 of the same Regulation testing on vertebrate animals shall be undertaken only as a last resort.

 

According to Annex XI of Regulation (EC) No 1907/2006 (Q)SAR results can be used if (1) the scientific validity of the (Q)SAR model has been established, (2) the substance falls within the applicability domain of the (Q)SAR model, (3) the results are adequate for the purpose of classification and labeling and/or risk assessment and (4) adequate and reliable documentation of the applied method is provided.

 

For the assessment of 2-piperazin-1-ylethanol (CAS 103 -76 -4) (Q)SAR results were used for aquatic bioaccumulation. The criteria listed in Annex XI of Regulation (EC) No 1907/2006 are considered to be adequately fulfilled and therefore the endpoint(s) sufficiently covered and suitable for risk assessment.

 

Therefore, and for reasons of animal welfare, further experimental studies on aquatic bioaccumulation are not provided.

Parent compound:

No studies are available for the bioaccumulation assessment of the substance. According to Regulation (EC) 1907 (2006) Annex IX, Section 9.3.2, Column 2, a study on bioaccumulation does not need to be conducted as the substance has a low potential for bioaccumulation. 2 -Piperazin-1-ylethanol has a measured log Kow of -1.47 (25 °C, pH: 10.5 – 10.9; BASF AG, 1989; report no. 105629, see IUCLID Ch. 4.7). Regarding these values, accumulation of the test substance in organisms is not to be expected. Therefore, and for reasons of animal welfare, a study on bioaccumulation is not provided.

 

However, in order to assess the bioaccumulation potential of the substance, the BCF was calculated with several estimation models. The table below lists the applied (Q)SAR models, the estimated BCF values and basic information on the applicability domain (AD). Detailed information on the model’s results and the AD are given in the endpoint study records of IUCLID Chapter 5.3.1. The selected models comply with the OECD principles for (Q)SAR models.

 

Summary of relevant information on aquatic bioaccumulation: Predicted BCF values for applied QSAR models sorted by BCF:

(AD = Applicability Domain)

Model	BCF [L/kg]	In AD	Restraints
BCFBAF v3.01 (EPI Suite v4.11): Arnot-Gobas BCF, upper trophic, incl. biotransformation	0.9	no	As the substance ionizes at physiologically relevant pH, the estimation may be less accurate.
BCFBAF v3.01 (EPI Suite v4.11): Arnot-Gobas BCF, upper trophic, incl. biotransformation of zero	0.9	no	As the substance ionizes at physiologically relevant pH, the estimation may be less accurate.
US EPA T.E.S.T. v4.2.1: Bioaccumulation: Consensus method	0.95	yes	-
KNN/Read-Across v1.1.0 (VEGA v1.1.5)	1.51	yes	-
BCF baseline model v03.10 (OASIS Catalogic v5.13.1.156): incl. mitigating factors	2.45	yes	-
BCFBAF v3.01 (EPI Suite v4.11): Meylan et al. (1997/1999)	3.16	yes	-
CAESAR v2.1.14 (VEGA v1.1.5)	3.7	yes	-
BCF baseline model v03.10 (OASIS Catalogic v5.13.1.156): not considering mitigating factors	9.23	yes	-

 

Considering all models applied the estimated BCF values range from 0.9 to 9.23 L/kg.

Predicted metabolites from Catalogic 301C v11.15 (OASIS Catalogic v5.13.1.156):

Metabolites (n = 20) from the degradation of 2-piperazin-1-ylethanol(CAS 103 -76 -4) were predicted using the QSAR model Catalogic 301C v11.15. The metabolites are identified by their SMILES code. The table below also lists the estimated quantity of appearance from the degradation as well as the log Kow and the biodegradability (BOD prediction). The metabolites with a quantity of > 0.001 mol/mol parent are regarded to be relevant for the environmental assessment. It was attempted to identify the relevant metabolites either via the QSAR Toolbox and/or the advanced search option for substances on the ECHA website. In case a name and/or CAS number was assigned, the PBT/vPvB status according to the ECHA website was checked.

Based on the available information, it can be concluded that all metabolites have a log Kow < 3. Seven of the 20 metabolites have a predicted quantity of > 0.001 mol/mol parent and are regarded as relevant for further assessment. Less than half of these metabolites (3/7) are not readily biodegradable (< 60% after 28 days, based on BOD), but all of these 7 metabolites have a log Kow < 3; therefore, a significant bioaccumulation potential is not expected. It can be concluded that these substances are not PBT/vPvB substances.

Their toxicity (T) was not further assessed as no critical combination of potential P/vP (= not readily biodegradable) and potential B/vB (log Kow > 3) properties was observed.

 

Table: QSAR prediction for CAS-#103 -76 -4 using CATALOGIC 301C v11.15 – July 2018 (OASIS CATALOGIC v5.13.1.156; metabolites with a quantity > 0.001 mol/mol parent (approx. 0.1%) after 28 d are highlighted by grey background and bold type; metabolite no: according to (Q)SAR model Catalogic v11.15 – July 2018 (OASIS CATALOGIC v5.13.1.156))

#	Metabolite No	Smiles	Substance name (CAS)	Quantity (mol/mol parent)	LogKow	BOD prediction (% after 28 d)	PBT-Assessment (ECHA (disseminated substances)
parent	1	OCCN1CCNCC1	2-piperazin-1-ylethanol (CAS 103-76-4)	0.000010	-1.47	28	not checked
1	2	O=CCN1CCNCC1	not identified	0.000010	-1.586	28	not checked
2	3	OC(=O)CN1CCNCC1	2-piperazin-1-ylacetic acid	0.006192	-3.357	22	not (pre-)registered
3	4	OC(=O)C=O	Glyoxylic acid (CAS 298-12-4)	0.007177	-1.403	100	not PBT / vPvB
4	8	C1CNCCN1	Piperazine (CAS 110-85-0)	0.975300	-0.799	1	not PBT / vPvB
5	15	OC1CNCCN1CC(O)=O	not identified	0.000000	-3.897	81	not checked
6	18	OC(C(O)=O)N1CCNCC1	not identified	0.000030	-3.585	15	not checked
7	19	OC1CN(CC(O)=O)CCN1	not identified	0.000002	-3.897	58	not checked
8	5	OC(=O)C(O)=O	not identified	0.000010	-1.736	100	not checked
9	9	OC1CNCCN1	not identified	0.000052	-2.337	75	not checked
10	16	OC(=O)CNCCNCC=O	not identified	0.000000	-4.454	81	not checked
11	20	NCCN(CC=O)CC(O)=O	not identified	0.000000	-4.709	22	not checked
12	10	NCCNCC=O	not identified	0.000000	-2.151	76	not checked
13	17	OC(=O)CNCCNCC(O)=O	not identified	0.000046	-4.788	80	not checked
14	21	NCCN(CC(O)=O)CC(O)=O	not identified	0.000898	-4.043	14	not checked
15	11	NCCNCC(O)=O	2-(2-aminoethylamino)acetic acid	0.007845	-3.922	73	not (pre-)registered
16	22	OC(=O)CN(CC=O)CC(O)=O		0.000000	-4.061	11	not checked
17	12	NCCN	1,2-Ethanediamine (CAS 107-15-3)	0.001139	-1.618	67	not PBT / vPvB
18	23	OC(=O)CN(CC(O)=O)CC(O)=O	2-[bis(carboxymethyl)amino]acetic acid	0.001473	-3.809	2	not (pre-)registered
19	13	NCC=O	2-aminoacetaldehyde	0.006952	-1.637	72	not (pre-)registered
20	24	OC(=O)CNCC(O)=O	not identified	0.000023	-3.274	81	not checked

Conclusion:

Based on the available information on the log Kow (log Kow = -1.47; measured; BASF AG, 1989, see IUCLID Ch. 4.7) and supported by a weight-of-evidence approach from calculated data, it can be concluded that

2-piperazin-1-ylethanol(CAS 103 -76 -4) and its metabolites are not expected to exhibit a significant bioaccumulation potential.